This invention relates to an apparatus which senses the level of a liquid in an internal combustion engine, and more particularly to low oil sensors for such engines.
Many types of liquid level sensors are known for internal combustion engines. One type of sensor is an electromechanical float switch. In a typical float switch, the float rides on the surface of the lubricating fluid, and is electrically connected to the engine ignition primary winding. A second contact is stationary, and is electrically connected to ground. When the lubricating fluid level falls below a pre-determined value, the two electrical contacts engage each other, and the ignition primary winding is grounded to shut off the engine.
Such float switches contain several mechanical and electrical components, and are relatively expensive to manufacture, assemble and maintain. Moreover, they tend to be inaccurate in that there is a great deal of turbulence in the engine fluid, causing the float to rise or fall substantially even though the level of the lubricating fluid is adequate.